Range hood air cleaning device

ABSTRACT

Disclosed is a hood structure for ventilating, primarily, commercial cooking ranges which is provided with an air intake slot defined by inwardly formed lip portions which aid in centrifugally extracting grease particles from air flowing through the hood. A continuous spray of water cools the adjacent lip portion and further removes grease particles and the like from the air stream. A separate, remote grease trap removes grease from the water draining from the hood.

Elite States Patent King 1 1 RANGE HOOD AIR CLEANING DEVICE [75]Inventor: Donald E. King, Louisville, Ky.

[73] Assignee: Ayr-King Corporation, Louisville,

[22] Filed: Sept. 13, 1973 [21] Appl. No.1 397,091 1 Related U.S.Application Data [63] Continuation-impart of Ser. No. 378,566, July 12,

[52] US. Cl 98/115 K,'55/l18, 55/122, 55/126, 55/228, 55/242, 55/259,55/267, 55/320, 55/436, 55/DIG. 36, 126/299 R, 210/513, 261/115 [51]Int. Cl 801d 47/06 v [58] Field of Search 55/228, 239, 240, 241,

55/260, 434, 436, 447, 461, 421, DIG. 36,

115 K; 126/299 R, 299 A, 299 B, 300, 301', 210/513, 532, 538; 261/115,116, 117, 118

[ 1 Dec, 17, 1974 2,813,477 Gaylord 126/299 A 2,868,108 l/1959 Petersen55/DIG. 36 2,971,452 2/1961 Grasswich et a1 SSIDIG, 36 3,021,777 2/1962King 55/D1G. 36

- 3,496,704 '6/1967 Bandlow... 55/316 3,364,664 l/l968 Doane 126/299 RX3,410,195 l1/l968 King 98/115 K 3,628,311 12/1971 Costarella 261/118 X3,653,179 4/1972 Doane 55/1 FOREIGN PATENTS OR APPLICATIONS 16,853 1911Great Britain 210/513 624,853 6/1949 Great Britain 126/299 B 724,6352/1955 Great Britain.... 55/240 960,621 6/1964 Great Britain 55/431'1,165,635 10/1969 Great Britain 98/115 K 354,917 7/1961 Switzerland55/D1G. 36

. Primary ExaminerDennis E. Talbert, Jr.

Attorney, Agent, or Firm Woodard, Weikart,

Emhardt & Naughton 57] ABSTRACT Disclosed is a hood structure forventilating, primarily, 1

stream. A separate, remote grease trap removes grease from the waterdraining from the hood.

1 Claim, 5 Drawing Figures PATENTEL SEC] H974 SHEEI 3 [IF 3 RANGE HOODAIR CLEANING DEVICE BACKGROUND OF THE INVENTION meeting thesedifficulties by merely dumping the eon-.

taminated ventilating air stream to atmosphere exterior of the buildingor enclosure.

The apparatus of the present invention utilizes a hood structureincorporating a centrifugal extractor,

internal portions. of the extractor being cooled by a continuous waterspray to prevent grease particles from baking on these surfaces. Thewater spray, flowing counter to the airflow, also serves to wash greaseand smoke particles from the air stream. The grease contarninated wateris moved through a separate grease trap assembly which accumulates thegrease entrained in the contaminated water, thus permitting thedecontaminated water to be returned to the conventional sewer drain orother drain facility.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a structureembodying the present invention.

FIG. 2 is a side sectional view of the structure taken generally alongthe line 22 of FIGQl.

FIG. 3 is a fragmentary view of the continuous spray nozzle assemblyshownin FIG. 2.

FIG. 4 is an enlarged side sectional view of a portion of the structureshown in FIGS. 1-3.

FIG. 5 is a side sectional view of the grease-trap apparatus utilizedwith, but remote with respect to, the structure of FIGS. 1 and 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring initially to FIGS. 1and 2, the apparatus includes a generally vertically arranged hoodstructure indicated generally at 10, the hood having a generallyvertically extending box-like configuration with a forwardly extendingupper portion 11. Generally triangularly shaped side members 12 extenddownwardly from the hood portion 11, the transverse portion 13 joiningthe side members and extending across the front face of the structure.As will be evident from FIG. 2, particularly, the side members 12 andthe transverse member 13 form a hood proper which overlies the cookingsurface 16 of a conventional cooking range. The range may be of the typeutilized in commercial kitchens and may include cooking elementssuitable for deep-fryand char-broil functions.

The hood structure thus includes an intake portion adjacent the hoodproper defined by the walls 12 and 13, a filter and electrostaticprecipitator section indicated generally at 17 and an outlet conduitindicated at 18 which may extend to and discharge from a poweredsomewhat more detail in my aforementioned copcnding application Justbelow the preeipitator cells 21, andextending transversely across theair flow path through the hood structure, is a removable, filter-22accessible through the removable panel 22a.

The lower wall 31 (FIG. 2) of the hood structure merges with an inclinedportion 32 of the front wall of the hood structure, the remainingportion of the front wall being formed by the vertical portion 33 andthe inclined portion 34. The horizontally elongated opening between theupper margin of the wall portion 32 and the lower margin of the wallportion 34 accommodates a generally tubular insert indicated generallyat 41. As will be evident from FIG.'1 there are two duplicate unitarytubular structures 41, only one being visible in FIGS. 2 and 4. Thestructure 41 is provided with a flanged margin 410 which extends intothe reversely flanged portion 34a of the wall 34 (FIG. 4). An inclinedflange 44b engages a similarly inclined flange 32a formed on theinclined wall 32. The structure 41 defines an opening or' slot 42 whichis bounded by an upper lip portion 43 and a lower lip portion 44. Theupper lip portion has a front panel 43a and a portion 43b which isturned inwardly and downwardly to merge with the vertical portion 43c.The wall 43c terminates short of the base wall 31 of the hood and at itslower margin is provided with an outwardly extending flange 43d.

The lower lip portion 44 is provided with a front wall 440, the inclinedlower marginal flange 44b, previously mentioned, and an inwardly turnedflange 44a defining the lower margin of the slot 42. The lower lipportion or flange 44a is spaced above the lower marginal flange 43d ofthe upper lip member 43 and the area available for flow of contaminatedair is narrowed by the oppositely extending flanges 44a and 44d, therebyincreasing the velocity of the air flow. Contaminated air entering theslot 42thus has its velocity increased and is directed downwardly, theinclined wall 32 and the base wall 31 of the hood structure functioningto reverse the flow of air, turning it upward, after it leaves themember 41. The increase in velocity'of the air stream and its abruptchange in direction centrifugally extracts the larger grease particlesfrom the air stream causing them to move into the area above the basewall 32.of the hood. This deposited grease and the water flowing fromthe continuous spray nozzle structure, to be subsequently described, isdrained from the interior of the hood structure through the drain pipe46 which is connected to the remote grease trap structure to besubsequently described with reference to FIG. 5.

As may best be seen in FIGS. 2, 3 and 4, there is supported just aboveand behind the wall 43c a series of continuous water spray nozzles 47.The nozzles 47 are fed froma header pipe 48, supported by means of abracket 49 within the hood structure, and supplied with cold waterthrough thepipe 51 (FIG. 2). As will be evident from FIG. 3, the sprayangle of the nozzles 47 is approximately 120 degrees and the spraypatterns overlap so that a curtain of water droplets is directed intoand counter to the air as it flows upwardly into the upper portion ofthe hood structure. As will be evident from FIG. 2, a portion of thespray issuing from the nozzles 47 engages and cools the walls 431) and430 of the lip structure 43, thereby holding the operating temperatureof these surfaces at a level such that grease droplets entrained in thecontaminated air moving through the slot 42 are not baked on the lipportion surfaces. The flow of water to the continuous spray nozzles 47and to the wash-down nozzles to be subsequently described is controlledby control elements not shown and not forming a part of the presentinvention but described in detail in my aforementioned copending patentapplication.

Slightly above and forwardly of the nozzles 47 is an array of upwardlydirected wash-down nozzles 52 and an array of inwardly directedwash-down nozzles 53.

Both sets of nozzles are supplied by the header pipe 54, the pipe 54being supplied at the desired intervals with warm water through the pipe56 which extends to the exterior of the hoodstruc'ture in side-by-siderelation to the pipe 51. Referring to FIG. 2, above the electrostaticcells 21 there is disposed a series of nozzles 57 which are alsosupplied with warm wash-down water through a pipe 58 which communicateswith the water inlet pipe 51 (FIG. 4) previously mentioned. Closelyadjacent the wash-down water nozzles 57 there is provided a series ofdetergent spray nozzles 59 which, at the desired intervals, providedetergent solution to the surfaces of the precipitator cells 21, thesequence of operation of these wash-down nozzles 57 and the detergentnozzles 58 being controlled by control apparatus not shown but describedin some detail in my aforementioned copending patent application.

Referring to FIG. 5, the apparatus for separating grease from the greasecontaminated water draining from the hood structure will now bedescribed. The apparatus includes a generally rectangular housing 71into which an extension of the drain pipe 46 extends. Supported on sidebrackets 72 within the housing is a receptacle 73 which, as indicated bythe arrows in FIG. 5, receives the contaminated drain water from thepipe 46. A removable access door 74 in the housing permits the removalof the receptacle 73 for purging it of accumulated grease. The interiorof the receptacle 73 is provided with an inverted-U shaped tube. One leg77 of the tube extends to the exterior of the receptacle at thereceptacle base and the other leg 78 of the tube terminates adjacent tobut above the receptacle base, the junctional portion 79 of the tubebeing disposed adjacent the upper margin of the receptacle 73. It willbe understood that grease is separated from the contaminated water bythe flotation principle, that is, grease accumulates at the surface ofthe water emptied into the receptacle 73, the water at the base of thereceptacle flowing through the leg 78 and the leg 77 of the tubularmember to exit through the drain 79. The water leaving the drain issubstantially clean and free of grease which accumulates in thereceptacle 73. i

In operation, when the range is in operation and the pressure in thehood structure is below atmospheric pressure, contaminated air will bedrawn through the slot 42 and will increase in velocity by its passagethrough the restricted area provided by the lip portions as it movescounter to the cold water spray from the nozzles 47.The surfaces of thelip structure, particularly portions 43b and 430 (FIG. 4)'will be cooledby the water spray. The air flow will continue through the filter 22 andthe precipitator cells 21 to exit through the flue 18 with greaseparticles and smoke particles removed. By a control sequence not shown,upon shutdown of the apparatus, the wash-down nozzles 52 and 53 and thedetergent nozzles 59 and wash-down nozzle 57 will be energized for thedesired time intervals providing a wash-down of the apparatus, the waterfrom the wash-down accumulating at the base 31 of the structure to becarried away by the drain pipe 46. The grease trap structure describedwith reference to FIG. 5 removes grease from this drain water permittingit to be emptied into conventional floor drains through the outlet 79(FIG. 5).

From the foregoing it will be evident that the contin uous water sprayfrom the nozzles 47 impinges on the surface of the lip structure coolingthese surfaces to that grease particles arenot baked on them. Thepreferred form of the structure utilizes the electrostatic precipitatorcells 21, although satisfactory results, under some conditions, can beobtained in hood structures in which these cells are eliminated. The lipstructure 41 forming the slot 42.can be removed from the hood structureby withdrawing the unitary structure provided by the lip portions 43 and44, and may be removed from the hood (the adjacent surfaces of theflanges 41b and 32a (FIG. 4) sliding with relation to each other) forcleaning and maintenance of the nozzle arrays which are accessible agterremoval of the lip structure 41 from the hood.

I claim:

1. Range ventilating apparatus for removing grease vapors, odors, smokeand the like including a hood structure overhanging and spaced above arange cooking surface, said hood structure having a vertically extendingbox-like configuration with a forwardly extending upper portion, anelongated horizontal slot formed in the front face of said box-like hoodstructure below said extending upper portion, said slotbeing defined bya unitary tubular structure removably inserted into said box-1ike hood,one wall of said tubular structure being fonned. to provide an upper lipportion at the upper edge of said slot turned inwardly and downwardlywithin said hood and terminating above the base of said hood, the otherwall of said tubular structure being formed to provide a lower lipportion at the lower edge of said slot, and outwardly directedhorizontally extending flange provided along the lowermost margin ofsaid upper lip portion and an inwardly directed horizontally extendingflange provided along the uppermost margin of said lower lip portion,saidhorizontal flanges providing a passage of reduced area therebetweenfor air and fumes within the hood structure, a series of spray nozzlessupplied with cooling water arranged along the rear surface of saidupper lip portion and within the hood structure for directing acontinubaked on the lip surface, and the removability of said unitarytubular structure permitting maintenance access to said spray nozzlesand the interior of said hood structure.

1. Range ventilating apparatus for removing grease vapors, odors, smokeand the like including a hood structure overhanging and spaced above arange cooking surface, said hood structure having a vertically extendingbox-like configuration with a forwardly extending upper portion, anelongated horizontal slot formed in the front face of said box-like hoodstructure below said extending upper portion, said slot being defined bya unitary tubular structure removably inserted into said box-like hood,one wall of said tubular structure being formed to provide an upper lipportion at the upper edge of said slot turned inwardly and downwardlywithin said hood and terminating above the base of said hood, the otherwall of said tubular structure being formed to provide a lower lipportion at the lower edge of said slot, and outwardly directedhorizontally extending flange provided along the lowermost margin ofsaid upper lip portion and an inwardly directed horizontally extendingflange provided along the uppermost margin of said lower lip portion,said horizontal flanges providing a passage of reduced area therebetweenfor air and fumes within the hood structure, a series of spray nozzlessupplied with cooling water arranged along the rear surface of saidupper lip portion and within the hood structure for directing acontinuous water spray downwardly within said hood structure to impingeon the rear surface of said upper lip portion, whereby when the pressurewithin said hood structure is below atmospheric, air and fumes from therange surface are drawn through said slot and provided increaseddownwardly directed velocity by the proximity to each other of saidhorizontal flanges and are then reversed to flow upwardly through saidhood structure, the water spray cooling said upper lip portion toprevent grease particles impinging thereon from being baked on the lipsurface, and thE removability of said unitary tubular structurepermitting maintenance access to said spray nozzles and the interior ofsaid hood structure.